Recently, with the rapid development of technologies, display products having a fingerprint detection function gradually come into people's lives and work. Due to uniqueness of fingerprints, the fingerprint detection technology has attracted much attention. Press-type and slide-type fingerprint recognition technologies on the basis of a silicon-based process have been integrated into a mobile product, and in future the focus of attention will be on the fingerprint recognition technology at a display region.
In a conventional photo sensor-based fingerprint detection unit, each fingerprint sensor consists of one photosensitive diode and one switching thin film transistor (TFT). In scanning a fingerprint, light beams from a light source may be reflected differently due to a difference between a valley and a ridge of the fingerprint, so the light intensity at the photosensitive diode may vary and thereby generate different photocurrents. Under the control of the switching TFT, the currents flowing through the photosensitive diode may be read sequentially, thereby achieving the detecting of the valleys and ridges of the fingerprint. However, the conventional fingerprint detection unit includes a plurality of switching TFTs, and in case that the performance of the switching TFT is deteriorated due to environmental facts, the switching TFT may be turned on or off erroneously. As a result, the fingerprint detection effect may be adversely affected. In addition, due to the switching TFTs, the aperture ratio of a display panel may be adversely affected.